An electronic component mounting machine that mounts an electronic component on a substrate is equipped with a component feed part where a plurality of part feeders, like tape feeders storing electronic components, are arranged side by side. The electronic component mounting machine iterates component loading operation including picking up an electronic component from one of the part feeders by use of a loading head and transferring and mounting the thus-picked-up electronic component on a substrate. A multiple loading head equipped with a plurality of suction nozzles is generally adopted in order to meet a demand for enhancement of operation efficiency. By virtue of adoption of the multiple loading head, the loading head can handle a plurality of electronic components as objects of mounting during a course of one mounting turn in which the loading head makes a reciprocal movement between the component feeding part and the substrate.
Such a multiple loading head requires a nozzle rotary drive mechanism that rotates a plurality of suction nozzles around respective nozzle shafts (see Patent Document 1). In the example described in connection with the patent document, a plurality of nozzle shafts are arranged in the form of a straight row. A driving belt is looped over driven pulleys coupled to the nozzle shafts, therefore a plurality of nozzle shafts are rotationally driven by a single θ-axis motor.